Blacklist / RBL Check

What is an RBL / DNSBL?

DNSBL (DNS-based Blocklist), also called an RBL (Real-time Blackhole List), is a list of IP addresses or domains associated with spam, phishing, or other abusive activity. Mail servers query these lists before accepting email — if the sending IP is listed, the message may be rejected or marked as spam.

This tool checks your IP or domain against 15+ major blocklists in parallel using DNS queries. If your IP is listed, contact the blocklist operator to request delisting. Each blocklist has its own delisting process and criteria.